docs: def _get_azimuth_correction(self, coe, azimuth):
          """
          This is the azimuth correction defined in the functional form (see
          equation 3 at page 2256)
          """
          term1 = abs(np.cos(np.radians(2.*azimuth)))
          term2 = abs(np.sin(np.radians(2.*azimuth)))*coe['a5']
          return np.log(np.max(np.hstack((term1, term2))))